Doha
I use Doha on a regular basis, and have no problem with Qatar airways or the transfer process. it is better to use the bus and go direct to the transfer termianl, NO extra security. 3 min walk to Eco exec lounge. The Bus to onwards faircraft.
I have never changed operators, but was aware that there was a plan to charge visa fees for transit pax....that heavens that its not for same airline transfers.
ps was in manila last week, and the new international terminal was next to my hotel, or should I say 30 mins by taxi, (as not open yet.).....